Art of enameling metal ware.



lUNrrnn dramas PATENT @rrron.

GEORGE W. KETCI-IAM, Oh NE\VARK, NE\V JERSEY.

ART OF ENAlvlELlNG METAL WAREZ.

SPECIFICATION forming part of Letters Patent No. 708,363, datedSeptember 2, 1902.

Application filed December 5, 1901. Serial No. 84,773. (No sncoimcnsl Toa, whom it may concern:

Be it known that I, GEORGE W. KETGHAM, a citizen of the United States,residing at Newark, county of Essex, State of New Jersey, have inventeda useful Improvement in the Art of Enameling Metal \Vare, of w iich thefollowing is a specification.

My invention relates to enameling metal, and more particularly steel andiron or a metal of which steel or iron is the base. Other materials,however, may be used. Preferably I use the ordinary sheet-steel ofcommerce, to which after applying a coating of any suitablenon-corrosive metal I apply one or more coats of an enamel composed ofsubstances which will coaot with and partially permeate the coatingmetal to produce after such enamel is fixed by heating an enamelcharacterized by a high gloss and having a peculiar mottled, wavy, orfoliated effect, which adds beauty and value to the article.

My invention consists in the process herein set forth as well as thearticle produced.

To carry my invention into eifecnl proceed as follows: The article to beenameled is first annealed and subsequently cleaned in any well-knownmanner-as, for instance, by immersing first in cold and then in boilingsoda solutions. After all grease and dirt have been removed and thearticle dried I apply a very thin cohesive coating of a non corrosivemetal. For sanitary goods I prefer to use copper; but for articlesemployed in cooking and to avoid any possibility of poisonous effeet Ipreferably use aluminium, although I may employ nickel or cobalt or anyof the non-corrosive metals. Such metals may be applied in any suitablemanner to produce a thin cohesive and smooth coating, as by immersingthe article in a solution of the salt of the metal with a suitableelectrode by electrodeposition or by rolling a thin film of the metalupon the article. My object in providing the metal which forms themetallic base of the article with a thin cohesive coating of anon-corrosive metal is for the purpose, first, of protecting the metalbase against the action of any acid or alkali contained in or developedfrom the enamel after heating; second, of filling the pores, cavities,and inequalities in the surface of the article incident to the characterof the base metal employed or due to manufacture, whereby when theenamel is applied it is applied to a smooth surface and to a metallicsurface which is not the surface of the base metal, but an appliedsurface with which it will coact to produce an enameled surface for thearticle having a high gloss and presenting a mottled,wavy, or foliatedappearance. After the layer of non-corrosive metal has been applied Ithen coat the article with an enamel having substantially the followingformula: feldspar, five hundred pounds; borax, three hundred pounds;soda-ash, fifteen pounds; saltpeter, fifty pounds; fluor-spar,twenty-five pounds; cryolite, fifty pounds, with the addition of anysuitable coloring-matter, such as cobalt or manganese. The boraxmentioned in the formula will after heating produce boracic acid, whichwill coact with the oxidized surface of the applied cohesive metalcoating and produce a chemical substance which will in turn coact withthe other substances and coloring-matter mentioned in the formula of theenamel to produce after heating the peculiar high gloss and wavy orfoliated appearance which characterizes the enamel produced by themethod and employment of the substances specified. The amount of boracicacid which should be developed upon heating the enamel should besufficient to act upon the oxidized surface of the metal coating, butnot sufficient to perforate the coating and act upon the metal base.

I do not limit myself to the precise proportions of the differentmaterials which compose the enamel, and I may substitute for one or moreof the ingredients other suitable ingredients. I may apply one or morecoatings of the enamel, as desired. After applying the enamel in theusual manner the article coated is placed in a muflie and heated in theusual way to flux and set the enaniel.

The article made by the process described will have produced on it anenameled surface of high gloss with great adhesiveness and that will notsplit or crack and which to the eye presents a distinctive mottled,wavy, or foliated appearance.

I am aware that it has heretofore been proposed to coat the metallicbase with another metal, thenjapply an enamel, and, fur

ther, to coat the metallic base with another metal and then apply anenamel which will eat through the coating metal and act upon themetallic base. Such, however, I do not claim to be my invention.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The herein-described process of enameling whichconsists first, in coating the cleaned article with a thin layer ofcohesive and noncorrosive metal, then applying an enamel which uponheating will coact with and only partially oxidize and permeate thecoating metal.

2. The herein-described process of enameling which consists first, incoating the cleaned article with a thin layer of cohesive andnoncorrosive metal, then applying an enamel which upon heating will setfree an acid in sufficient quantity and strength to coact with and onlypartially oxidize and permeate the coating metal.

3. The herein-describedprocess of enameling which consists first, incoating the cleaned article with a thin layer of cohesive andnoncorrosive metal, then applying an enamel composed of feldspar, borax,soda-ash, saltpeter, fiuor-spar, cryolite and a coloring-matter in suchproportions that such enamel will upon heating partially oxidize andpermeate the metal layer, and finally heating to flux and set theenamel.

4. The herein-described process of enameling which consists in coatingan iron or steel body with a thin layer of cohesive and noncorrosivemetal, then applying an enamel which upon heating will coact with onlythe outer surface of the coating metal.

5. The herein-described process of enameling which consists first, incoating the cleaned article with a thin layer of cohesive andnoncorrosive metal, then applying an enamel composed of fusiblematerials and a coloringmatter, and which enamel upon heating will setfree an acid which will coact with and only partially oxidize andpermeate the noncorrosive coating, and act upon the coloringmatter, toproduce in the finished article a surface having a high gloss and a wavyor foliated appearance, and finally heating to flux and set the enamel.

6. The herein-described process of enameling which consists first, incoating the cleaned article with a thin layer of cohesive andnoncorrosive metal, then applying an enamel which upon heating willdevelop boracic acid sufficient in quantity to only partially oxidizeand permeate the applied metal coating, and finally heating to flux andset the enamel.

7. As a new article of manufacture, a metallic vessel or other articlecarrying a superposed film of another metal partially oxidized andpermeated in spots, and upon said film an enamel or glaze.

8. As a new article of manufacture, a vessel or other article having abase of a corrosive metal, an enameled surface, and a layer ofnon-corrosive metal, partially oxidized and permeated in spots,interposed between the base and the enamel.

9. As a new article of manufacture, a metallic vessel or other articlehaving its entire surface, pores, indentations and inequalities coveredand filled with a thin cohesive layer of metal, said layer of metalpartially oxidized and permeated in spots, and an enamel coatingsituated over said metal layer.

In testimony whereof I affix my signature in the presence of twowitnesses.

GEORGE W. KETCHAM.

Witnesses:

J. E. PEARSON, O. E. STECHER.

